The ending scene originally featured Johnny Fever playing Eagles' 1980 hit "The Long Run". Syndicated versions also included this song. Unfortunately, Shout! Factory's 2014 DVD release was unable to license the song, so replaces it with a similar generic song and has dubbed the original actors lines. This ultimately ruins the joke where Andy is yelling ecstatically that Fever is playing a hit.
In Johnny Fever's apartment you can see a poster for The Blue Wisp Jazz Club on the back of his front door. This was an actual famous Cinncinati club that features huge acts. It closed in June 2014.
Johnny's daughter looks at a picture on Johnny's wall and says, "Wow, you know Mick Jagger?" The picture is in fact of Mick Jagger and Howard Hesseman taken in 1969 during The Rolling Stones' promo for Music Scene (1969).
Mr. Carlson has several times pretended to be someone other then himself at the other WKRP staff members behest.
The magazine that Jennifer reads is the November 1979 edition of Paris Vogue.